meldrum



No. 6l4,569. Patented Nov...2.2, |898.

J. .1.- & T.VF. MELnnuM & w.'THoMsoN.

FURNACE.

(Application led Aug. 31, 1896.)

- 3 Sheets-Sheet I.

(No Model.)

ffy/Mm Tn: Nnms PETERS co, Pncn'uumo., WASHINGTON, D. c.

No. 6l4,569. Patented Nov. 22, |898. J. J. & T. F. MELDRUM W. THOMSON.

F U R N A C E.

(Application iled Aug. 31, 1896.)

3 Sheets--Sheet 2.

(No Model.)

ma NoRms PETERS co. PHOTO-umu.. wlmNaToN. n. c.

No. 6I4,569. Patented Nov. 22, |898.

J. J. & T. F. MELDRUM & W. THOMSON.

F U R N A C E (Application filed Aug'. 31, 1896.)

3 Sheets-Sheet 3.

(No Model.)

me Nonms PErERs co, vHoTaLn'No.. wAsmNm'oN. n. c4

UNITED STATES PATENT EEIOE.

JAMES JONES MELDRUM AND THOMAS F. MELDRUM, OF MANCHESTER, ENGLAND, ANDWILLIAM THOMSON, OF'GOVAN, SCOTLANDq FU RNACE.

SPECIFICATION forming part of Letters Patent No. 614,569, dated November22, 1898.

Application filed August 31, 1895. Serial No. 604,416. (No model.)

To all whom t may concern:

Be it known that we, JAMES JONES MEL- DRUM and THOMAS FREDERICK MELDRUM,engineers, of Manchester, in the county of Lancaster, England, andWILLIAM THOMSON, engineer, of Govan, in the county of Lanark, Scotland,subjects of the Queen of Great Britain, have invented certain new anduseful Improvements in Furnaces, of which the following is aspecification.

' The invention has been patented in England, No. 20,622, dated November27, 1891.

This invention has reference to furnaces in connection with which forceddraft is ernployed; and it has mainly for its object to constructorprovide means,in connection with the furnaces, whereby they can beworked-that is, red-with greater effect and efficiency at all times,including such times when the fires.

are cleaned and when the door or doors is or are of necessity opened.

In the drawings which serve to illustrate our invention we show itsapplicationto some different examples of furnaces.

In the examples, Figure l is a sectional elevation of an internalfurnace, and Fig. 2 is an end view of same with part of the plateinclosing the ash-pits broken away. Fig. 3 is a sectional elevation, andFig. 4 an end view, of an under-fired or externally-fired7steam-generator provided with our improvements. Fig. 5 is an end Viewshowing another arrangement of furnace and parts.

In all of these arrangements and applications there is provided,inconnection with each separate ash-pit, a steam-j et blower or blowers,and such blowers are in every case disposed horizontally and mainlywithin said ash-pit; but this arrangement is not essential.

Referring now to the drawings, X is the shell of the steam-generator.

a' a2 are the two separate ash-pits in each case, and a3 the partitionseparating said ashpits.

b b2 are the blowers for the ash-pits a and a2, respectively.

c are the fire-bars forming the grate.

cl is the common furnace-space or combustion-,space above the grate.

e is or are'the fire door or doors, as the case may be.

ff2 are the steam-pipes,having each a regulating-cock f3 thereon.

h is the plate or plates, as the case may be, inclosing the ash-pits aa2 and in and by which the blowers are fixed and supported.

fi' is or are the door or doors bywhich access to the ash-pits a. and a2is had for any desired purpose.

c' are the bearers, which support the firebars c.

In operating according to this invention in some cases it is preferredto use such a pressure in the ash-pits as will cause the pressure abovethe grate-to be about equal to that of the atmosphere, so that when thedoor e is open the flames will not blow out.

In furnaces constructed as described it will be seen that while thegrate formed by the firebars c is a single one each of the ash-pits a a2is entirely separate, and the delivery to and maintenance of air underpressure in themV is separately performed by separate air-forcing means,and the furnace-space CZ is, as the grate, common to these two ash pits,and thus while that part of the operation of combustion of the fuelconnected with the parts of the apparatus below the grate is separatelyand distinctly performed in the separate ashpits the actions takingplace above the fuel over the whole of the grate are common andunrestrained in all ways, and consequently the gases and ames generatedare free to intermingle and become naturally intermixed.

The operation of effecting combustion of the fuel is carried on asfollows: The feeding and burning of the fuel on the di'erent parts ofthe grate are carried on in an alternating method, so that on one sideof the grate, above one ash-pit, green fuel will exist after stoking andon the other coke only or fuel in a full state of combustion, and withthe fuel thus in different stages of combustion the heat and flames ofthe one iu a full state of combustion insures the combustion of thefreshor green gases being distilled from the fresh coal on the otherside, as by the forced draft-viz., the air under pressure in theash-pits-the iiames and gases from all parts of the fuel naturallybecome intermixed, whereby the combustion of all such gases is eifectedand the dischargeof smoke pre1 IOO vented. Moreover, the supply of airto the separate ash-pits being under separate control-that is, byadjusting the steam-supply to the steamjet blowersthe rate of combustionand the regulation of the furnace at the opposite sides are entirelyunder control, whereby a continuous or substantially continuous andconstant temperature of the combined gases given oif from the fuel in asingle furnace is effected and an improved efficiency obtained.Furthermore, when the one side of the grate or furnace is being cleanedthe air-supply to the ash-pit below that side is cut off by the cock f3on the steam-pipe connected with that side, the other ash-pit workingunder normal conditions. Thereby in a single orcommon furnace proper ameans of cleaning alternately the different sides of the grate withoutinterfering with the maintenance of the required temperature, working,and eect is provided.

The application of the invention shown in Figs. 1 and 2 is to aninternally-fired steamgenerator-that is, a steam-generator having acircular metal furnace surrounded with water of the generator. Theash-pits a' a2 in this case are separated by a partition-plate a3, heldat its upper pa rt by lire-bars and at the front end between the webs77.'. In this case one ash-pit door only common to the two ash-pits a'a2 is provided; but in lieu of this separate ash-pit doors-viz. oneforeach ash-pit-may be provided on the plate 71 if desired.

In the arrangement shown in Figs. 3 and Li the partition a3 is shown asa brick wall, the front end of which lies between the webs 71,', and atthe top where the joint or connection is made with the grate specialinverted-T- shaped bars c2 are provided, the horizontal part of suchbars being sufficiently far enough from the grate-bars to prevent theashes which lodge upon them reaching the fire-bars.

In the arrangement shown in Fig. 5 the furnace shown is provided withtwo furnacedoors e, one above each of the ash-pits, the partition asbeing a brick one and having an inverted-T bar c2, as in Figs. 3 and 4.This figure represents the front view of a furnace for heating steam orwat-er, say for steam generation, or a furnace of any other kind or forany other desired purpose. This construction of furnace having separatedoors e to the common furnace-space or combustionu space above the grateand the separate ashpits ct' a2 is adapted better in cases where thefurnace is large.

This construction and arrangement of furnace, together with the inode ofcarrying on the burning of the fuel, is particularly useful andeffective in the burning of small and poor fuels or materials dicult ofcombustion by air alone.

In a single furnace operated after the method and constructed as hereindescribed and where the air is supplied and pressure in the ash-pitsmaintained above that of the atmosphere by means of forced draft thetemperature of gases given off and coming from the furnace ispractically constant or uniform; also, by stokin g and working theopposite sides of the furnace at different times the gases given offfrom the fresh fuel, mix ing with those of a higher temperature on theopposite side, are readily burned andthe obviation of the formation ofsmoke effected, and, moreover, when the furnace is cleaned at one sideand the bars more or less bared the entrance of a large volume of coldair into the furnace is practically wholly prevented.

l. A furnace having the free combustionspace above the grate in whichthe gases of combustion have freedom for movement and admixtu re; aplurality of closed and separate ash-pits under the said grate,disposedV side by side in relation to the point from which the furnaceis worked whereby the grate is divided into two portions capable ofbeing worked independently, and means for supplying the air to saidash-pits separately, at a pressure above that of the atmosphere and forregulating and controlling such supply, said free combustion-space beingcommon to both portions of the grate and being without division and thesaid grate being in the same horizontal plane throughout, substantiallyas and for the purpose set forth.

2. A furnace consisting of the combination of a main combustion-spaceabove the grate on which the fuel is borne and burned by air, aplurality of closed ash-pits under the grate, arranged side by side, andseparated by partitions extending vertically and longitudinally oftheash-pits,'said partitions reaching only to the grate but not above thesame, redoors at the front of the furnace and over such ashpits,fro1nwhich the fuel on the grate above each of said ash-pits is worked in thedirection of the length of said grate and ashpits, and means forsupplying air to said ashpits separately at a pressure above that of theatmosphere, and for regulating and con trolling such supply, the saidcombustionspace being common to all portions of the grate for the freemovement of the gas from one portion to the other and the said gratebeing in the same horizontal plane throughout, substantially as and forthe purposes set forth.

3. A furnace consisting of the combination of the grate c, on which thefuel is borne and burned by air; a common combustion-space cl above thegrate; a fire-door e through which the fuel on the grate c is worked;ash-pits a' a2 under the grate .0; a partition a3 separating theash-pits; steam-jet blowers b' b2 for supplying air separately to theash pits; steam-supply pipes f f2 and regulating and controllingsteam-supply cocks f3; substantially as set forth.

4. A furnace consisting of the combination of the grate con which thefuel is borne and burned by air; a common combustionspace IIO b abovethe grate 5 a ire-door e through which the fuel on the grate is worked;ash-pits 'a' o2 under the grate c; a partition o3 separating theash-pits a plate h inolosing the front of the ash-pits; steam-jetblowers b' b2 for supplying air separately to the ash-pits, oonneeted bytheir heads to the plate h, and the bodies whereof are disposedhorizontally and within the ash-pit under the grate; steampipes f f2 forsupplying steam to said blowers; and cooks f3 on said pipes forcontrolling said supply separately of each blower, and doors i in theplate h for gaining access to the ash-pits; substantially as set forth.

In testimony whereof we have hereunto 'set 15 our hands in the presenceof the subscribing witnesses.

JAMES JONES MELDRUM. THOMAS F. MELDRUM. WILLIAM THOMSON.

Witnesses to the signature of James Jones Meldrum:

THos. BURRow, WM. MORTIMORE DIDSBURY.

Witnesses to the signatures of Thomas F. Meldrum and William Thomson:

J oHN LINDsoN, JAMES JOHN CAIRNS.

